What is “fatty liver” disease, or NAFLD ?

In collaboration with Liver4Life

Fatty liver, or Non-Alcoholic Fatty Liver Disease (NAFLD) as it’s medically known, is a term used to describe an accumulation of fat in the liver. NAFLD covers a spectrum of liver conditions, ranging from simple steatosis to steato -hepatitis (NASH) and cirrhosis. My Liver Exam, in collaboration with Liver4Life, tells you what it entails.


 ®Oleksandra Naumenko

Definition of NAFLD

NAFLD is usually seen in people who are overweight or obese.

But first, what is the definition of obesity?

WHO (World Health Organization) defines obesity as an excess of weight by increasing the fat mass of an individual.1

However, it has been found in people of a normal weight whose diets are very high in fat and/or sugar content. A healthy liver should contain little or no fat. But for most people, carrying a small amount of fat in the liver causes no major problems. Having high levels of fat in your liver is also associated with an increased risk of problems : diabetes, heart attacks and strokes.2

The term NASH (Non Alcoholic Steato Hepatitis) is used when the liver cells can become inflamed, due to the presence of fat for a prolonged amount of time. NASH may progress, like many liver diseases, to cirrhosis and liver cancer.

What are the risks linked to NAFLD?

See the diagram below:


Steatosis Inflammation Fibrosis Cirrhosis
Accumulation of fat in the liver. Local response, due to harmful stimulus in the liver. Then, it may  leads some liver cells to increase in form (ballooning), and eventually die.3

An obsolete term for cells that are infected with certain viruses. It results in conspicuous swelling of the cell and cytoplasmic vacuolation. 3

Formation of excess scar tissue when hepatic cells are have been damaged.


Uncontrolled regeneration of the liver. It combines scar tissue (fibrosis) and cell clusters that do not respect the normal architecture (nodules).

You’re at an increased risk of Non Alcoholic Fatty Liver Disease if you:
• Are obese or overweight – particularly if you have a lot of fat around your waist (an “apple-like” body shape). (2)
• If you have type 2 diabetes. (2)
•If you  have high blood pressure. (2)
• If you have high cholesterol. (2)
• If you are over the age of 50. (2)
• And if you smoke. (2)

It seems that the majority of patients with fatty liver experience very few silent symptoms. They may complain of extreme tiredness, feeling sick and a pain around the liver area. If you are worried about Non Alcoholic Steato-Hepatitis/ fatty liver or the health of your liver, it’s a good idea to visit your GP and request a liver function test. He/she is the only one able to determine whether further investigation is required.

Therefore, alcohol is not the cause of Non Alcoholic Fatty Liver Disease, but drinking may make the condition worse.  It is advisable to cut down or stop drinking alcohol.2

One example : the situation in the UK

For example, in the UK population, about 1 in 3 have NAFLD4, and 2-5% have NASH.4

It is now the commonest cause of liver disease in the West and accounts for a growing proportion of patients undergoing liver transplantation (15-20%).4 Most patients commonly present in middle age.4

Besides, children are also at risk. Hence, there are possibly 60,000 10-year-olds with fatty liver, according to child measures of obesity. Extrapolating this for children aged 5–15 years, up to 500,000 children may already be at risk of developing an underlying liver disease that could lead to cirrhosis in the future.5

In conclusion, we know that NASH and NAFLD are major issues. Seems like excessive alcohol is not the only cause of liver disease, as people might think. As a result, to avoid a fatty liver, the first step is to adopt a healthy way of life. It combines a healthy diet, to a regular physical activity. For more information, you can check our page about liver prevention.

Associated content : What is liver steatosis?


  1. http://www.who.int/topics/obesity/fr/
  1. NHS Choices. Non-alcoholic fatty liver disease (NAFLD). http://www.nhs.uk/conditions/fatty-liver-disease/Pages/Introduction.aspx Accessed 23 Feb 2017.
  1. https://en.wikipedia.org/wiki/Ballooning_degeneration and http://www.medilexicon.com/dictionary/23283
  1. British Society of Gastroenterology. 2017. Commissioning evidence-based care for Patients with Gastrointestinal and Liver Disease. http://www.bsg.org.uk/clinical/general/commissioning-report.html Accessed 23 Feb 2017.
  1. Cheung CRLH, Kelly DA (2011) Non-alcoholic fatty liver disease in children. British Medical Journal 343; d4460